In the next ten years, the central railway station area in Utrecht will be reconstructed to dramatically improve the infrastructure. This revamp will involve increased construction work traffic and have a knock-on effect on the construction project progress and other city centre traffic. Within CIVITAS MIMOSA, Utrecht is implementing a co-ordinated approach to minimise the disturbance of the urban transport system and the polluting emissions. It will also concentrate on reducing the waiting times for vehicles unloading at construction sites and the amount of storage space needed at the construction site. Peaks in demand or in construction work traffic can be levelled out during the day with the new 4-D planning tool.The 4-D planning software is the latest trick up Utrecht’s sleeve, following the Construction Logistics Plan and the set-up of a Construction Logistics Centre near the central station. With this 4-D planning tool, the expected intensity of the road use can be visualised, based on the planning of construction projects. Armed with this information, congestion can be forecast and solved by e.g. changing the time schedule of certain construction vehicles, by designating corridors for construction traffic or by altering traffic lights at certain intersections.In order to use the tool properly, information on all the Central Railway Station construction projects are currently being collected. This detailed information includes a schedule of works, planning relations between various projects and information on the construction site, such as entrance and exit roads and available space for vehicles. Information will also include the identification of (un)loading zones, supply routes, storage space, cycle and pedestrian facilities and parking areas for construction workers.The 4-D planning will then gather and process this information to optimise construction logistics, traffic circulation and general accessibility of the area. The Central Station’s project management team are now gaining experience with this tool. The first evaluation results are expected in spring 2011.